In pictures: RMT Union leader Bob Crow dies of heart attack aged 52

Bob Crow, the socialist leader of the Rail, Maritime and Transport union who led the tube and railway workers union since 2002 and oversaw a series of strikes over pay and conditions, has died aged 52. The RMT union made the announcement "with the deepest regret". A brief statement said: "It is with the deepest regret that RMT has to confirm that our general secretary Bob Crow sadly passed away in the early hours of this morning.Picture: Dominic Lipinski/PA